Clutch



June 23, 1936. e. w. EMRICK 2,045,452

CLUTCH Filed May 5, 1954 INVENTOR foeafM f/me/c/r Patented June 23, 1936 UNITED STATES PATENT OFFICE Appma 14 olFims: (0121 I This invention relates to clutch devices and to' the method of constructing clutch devices and particularly to the facing, friction or gripping surface thereof; and the object of the invention is to provide a clutch, the face of which is ,composed of suitable fibrous material, such for example as asbestos or asbestos cloth or paper impregnated with a thermoplastic or similar material or a thermo setting type of phenol condensating resin, and still further, to the heat treatment of the friction surface ofa clutch element of this kind so as to displace the fluid content at the surface of the impregnated material and to harden said surface onto substantially carbonize the same without rendering such surface excessively brittle; a further object being to form grooves in the friction surface to reduce the contact area thereof as well as to provide lubricating or other channels in such surface; a further object being to provide a clutch of the class described in the a drawing forms a part, in which the separate parts of my improvement are designated by suitable 5 reference characters in each of the views, and in which:

Fig. 1 is a sectional view of a clutch unit assemblage indicating one use of the invention, the section being on the line ll of Fig. 2. 40 Fig. 2 is a section on the line 2--2 of Fig. 1. a

Fig. 3-is.a sectional view of a tubular blank from which a clutch such as shown in Figs. 1 and 2 is formed.

Fig. 4 shows the next step in shaping the blank 45 .shown in Fig. 3.

Fig. 5 shows the step of heat treatingtheworkpiece. I r

Fig. 6 shows the next step in forming the clutch.

Fig. 7 is a plan view of the clutch shown in.

50 Fig. 6 indicating the next step in the operation f producing the same; and, Fig. 8 is a section on the line 8-8 of Fig. "l.

For the purpose of illustrating one use of my invention, I have shown in Figs. 1 and 2 of the 55 drawing, a clutch unit or assemblage which constitutes apart of the clutch mechanism described and claimed in a companion application filed May 5, 1934, and bearing Serial No. 724,109.

In Figs. 1 and 2, III represents a driven spindle or shaft, the upper end of which-is provided with a cylindrical head I I on which is slidably and rotatably mounted a coupling block- I! forming part of a universal joint mounting of the spindle. A

pin 13 is passed transversely through the block It at right angles to the arrangement of the head 10 ll therein, and the block I! is rotatable on the pin !3 as well as being movable longitudinally thereof. The cylindrical head It is yoke-shaped in form to clear the pin [3 as disclosed in said companion application. 15

At It I have shown one of my improved clutch members or facings, and this member is shaped to form conical, clutch or friction faces l5 and I6 subdivided by a circumferential groove II central- 1y of said member. The facing l5 has a plurality of grooves l8 formed therein to reduce the contact area of the surface l5 as well as to provide oil orlubricating channels in such surface, whereas the surface It has similar grooves 19 which are less in number than the grooves IS. The member M has a dove-tailed split 20 at one side thereof to providefor the extension and contraction of said friction member in the use thereof. A pad or strip 2| of felt or other material is-arranged in the split 20 to act as a distance piece and also to'aid in supporting the lubricant when employed in conjunction with the clutch.

The member I4 is provided with 'a bore 22 extending therethrough at right angles to the split 20 for receiving the pin i3. :This pin is held against displacement by a spring ring- 23 which seats in the groove II, the ring 23 also serving to hold the felt strip 2| against displacement. In the bore of the member H is a split tube 24 preferably composed of spring material, and this tube is apertured to receive the pin l3 and serves or pressed fibrous material impregnated with a thermo setting material in the class of synthetic resins, phenols and the like. For the purpose of giving one illustration, the tube 25 may becomposed of asbestos cloth or paper impregnated with a thermoplastic material or a thermo setting ma-.

terial in the class of synthetic resins or phenols. After producing this tube of a'desired length and thickness, the same is shaped to form temporary conical friction surfaces l5 and IS, a groove H as 5 well as the bore or aperture 22.

After forming the tubular-blank 25 in the manner indicated in Fig. 4 of the drawing, I place in the bore 26 thereof, a rod or mandrel 27 which serves as a means of handling the workpiece as 10 well as a cooling'agent for the inner wall structure of the workpiece when subjecting it to the heat treatment of a heater ring or other heating element 28. In this connection, if desired, means may be provided for cooling the mandrel. This 15 ring or element may be composed of cast iron,

nichrome or other material.

In forming the member If herein disclosed, the heating element'28 is heated to approximately 1400 Fahrenheit, and is removed from a heating 20 furnace and the member I4 is placed in the ring 28 so that one friction surface l5-l6 is disposed in engagement with the conical heating chamber 28a of the element 28 in the manner indicated in Fig. 5, to subject such surface to the heat of the 5 ring. This heat treatment takes but a short period of time, and during the treatment, the fluid contained at the surface of the member being treated will be drawn from said surface and discharged through the lower open end 2817 of the 30 element 28, and the heat treated surface will be converted into a relatively hard coating'or layer which might be termed a .carbonization of the surface to such a degree as to provide a smooth hard surface which is reinforced, strengthened and supported by the fibrous body of the member as a whole. The depth or thickness of the treated surface will depend upon the degree of treatment as well as other characteristics of the impregnated fibrous material employed. In Fig. 1

40 of the drawing, the stippling at l'5a, l6a indicated the'heat treated outer surface. a

After one surface of the member I 4 has been treated, the other surface thereof will be treated in a similar manner, it being desirable to allow 45 the member to cool slightly between each treatment. By using a series of mandrels as well as a v number of theheating elementsm employed, a successive series of heat treating operations may be performed on different workpieces.

50 After both beveled surfaces I5, l6 of the meme ber 14 have been heat treated, the same are around or otherwise finished to the desired size andcontour. The next step in the method consists in forming the grooves l8 and IS in the sur- 55 faces l5 and I6, and then the member I is split in the angular manner indicated at 20 in Fig. 7 of the drawing so as to provide a substantially dove-tailed recess between adjacent cut or split ends ofthe tubular member or body H to receive 60 the pad 2|. I

The member I4 is now complete-and ready for assemblage of the spring sleeve 24 and spindle l therewith as'well as the pin l3, pad 2| and ring 23. It will be understood that the impregnation 0.5 of the member I lwith fibrous material employed therein is relatively slight, that is to say, there is no excessive amount of the synthetic resins or other impregnating material employed beyond the saturating point.

70 It will therefore be seen that in the heat treatment above referred to and in removing the fluid of the impregnating substance from the surface of the member If, what remains on the surface is the fibrous material and a part of said impreg- 75 nating ubstance in the form of a hard, smoo h surface body or facing which in its characteristics gradually fades into the normal fibrous saturated body constituting the core or inner body structure of said member, thus providing aresilient or yielding support which eliminates to a large degree the possibility of chipping, flaking or cracking, and maintains substantially the full strength and toughness of the original body. The heat treated surface having been subjected to relatively high degrees of heat will adapt the 10 member Hi to the normal or any excess heat which may prevail in its operation as a friction element without destruction or change in the characteristics of said preformed and heat treated friction surface.

It will be understood that my invention is not necessarily limited to the production of a friction member of the specific kind or shape herein disclosed nor for the use herein intended. My improved method is applicable to friction members or elements of any kind or class, and particularly where the friction member operates in oil or is subjectedtoexposure to a lubricant, and various other changes in and modifications of the construction and method herein disclosed may be made within the scope of the appended claims without departing from the spirit of my invention or sacrificing its advantages.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A friction member comprising a body of heat resisting fibrous material including a thermoplastic binder, and the binder being carbonized at the outer bearing surface of said body for a predetermined depth only of the body.

2. A friction member comprising a body of heat resisting fibrous material including a thermoplastic binder, the binder being carbonized at the outer bearing surface of said body for a predetermined depth of the body, and the remainder of the body inwardly of said outer bearing surface and including the'fibrous material at such surface serving to support and maintain said surface.

3. A friction member comprising a body of heat resisting fibrous material including a thermoplastic binder, the binder being carbonized at the outer bearing surface of said body for a predetermined depth of the body, the remainder of the body inwardly of said outer bearing surface and including the fibrous material at such surface serving to support and maintain said surface, and said surface being beveled and grooved.

4. A friction member comprising a body of heat resisting fibrous material including a thermoplastic binder, the binder being carbonized at the outer-bearing surface of said body for a predetermined depth of the body, and said body being in the form of a split tube.

5. A friction member comprising .a body formed 00 from layers of heat resisting fibrous material including a thermoplastic binder, one surface of said body being shaped to form a friction surface, the binder of said friction surface for a predetermined depth of the body including the thermoplastic'binder in carbonized form. r

6. A friction member comprising a tubular body formed from. circumferential layers of heat resisting fibrous material including a thermoplastic binder, one surface of said tubular body being beveled to form a friction surface, and the" binder of said friction surface for a predetermined depth of the body including the thermoplastic binder in carbonized form, and the carbon surface being Supported-and reinforced by the fibrous material of said body including the uncarbonized binder thereof.

7. A friction member comprising a body formed from layers of asbestos paper including a thermoplastic binder, one surface of said body for a predetermined. depth comprising asbestos and the thermoplastic binder in carbonized form.

8. A friction member comprising a body formed from layers of asbestos paper including a thermoplastic binder, one surface of said body for a predetermined depth comprising asbestos and the thermoplastic binder in carbonized form, said body being tubular in form, and the friction surface thereof being beveled.

9. A friction member of.high heat resisting properties, comprising an asbestos body treated with a thermoplastic binder, one surface of said body constituting the friction surface, said friction surface comprising a layer extending a predetermined depth into the body and being composed of asbestos and a carbonized binder, and said surface being supported and reinforced by the non-carbonized treated asbestos constituting the remainder of said body.

10. A friction member of high heat resisting properties, comprising an asbestos body treated with a thermoplastic binder, one surface of said body constituting the friction surface, said friction surface comprising a layer extending a predetermined depth into-the body and being composed of asbestos and a carbonized binder, said surface being supported and reinforced by the non-carbonized treated asbestos constituting the remainder of said body, said body being in the form of a split tube, and the friction surface of said tube being beveled.

11. A friction member of high heat resisting properties comprising a tubular body formed from a wrapped asbestos strip including a thermoplastic binder compressed therewith, one surface of said body constituting the friction surface, and said friction surface being formed by the asbestos of said body and the binder in carbonized form.

12. A friction member comprising a body of fibrous material of said body consisting of a major 1 part of asbestos, and the thermoplastic substance comprising a phenol condensating resin.

14. A friction member of high heat rt sisting properties comprising an asbestos body impregnated with a thermoplastic material, said body being shaped to form a beveled friction surface thereon and to provide means for mounting the body in connection with a support, the thermoplastic material at the friction surface of said body being carbonized for a predetermined depth, and the asbestos and carbonized material at such surface being yieldably supported by the remainder of the impregnated asbestos material.

GEORGE W. EMRICK. 

